Question

1. neglecting friction and air resistance, where is one contact force at time 1?

energy transfers and contact forces in the launcher, cart, box, and track system

between the cart and the box
between the box and the air
between the cart and the track
between the launcher and the cart

Explanation:

A contact force is a force that occurs when two objects are in physical contact. At time 1, the launcher and the cart are in contact. The force between the cart and the box (if any) would be when they collide (time 2 onwards). The box and air - air resistance is neglected. The cart and track - normal force is there but it's a non - applied contact force in the context of the system's energy transfer (the problem might be focusing on the applied contact force for launching). The launcher and cart have an applied contact force at time 1 for launching the cart.

Answer:

Between the launcher and the cart